Ferrule for furnace tubes



1% 3933, T. B. FISHER 1,927,163

FERRULE FOR FURNACE TUBES Filed July '7 1930 -Patented Sept. 19, 1933 UNITED STATES FERRULE FOR FURNACE TUBES Teddy B. Fisher, Chicago, Ill.,

assignor to Universal Oil Products Company, Chicago, 111., a corporation of South Dakota Application July 7, 1930. Serial No. 466,087

Claims. (01. 285-30) moval of .the tube through the tube sheet when' the ferrule is not in place and maintains a relatively tight joint between the tube and the tube.

sheet when the ferrule is in place, preventing 1O leakage of furnace gases from the inner to the outer side of the tube sheet around the tubes and preventing the infiltration of air around the tubes.

Other features and advantages of my invention will be apparent from the accompanying drawing and following detail description.

In the drawing, Fig. 1 is a sectional elevation of my novel ferrule operatively disposed in a tube sheet, and illustrates particularly a fastening means therefor.

Fig. 2 is a similar view to that shown in Fig. 1 without the fastening means.

Fig. 3 is a sectional view of a slight modification of my invention.

Fig. 4 is a front elevational view of the device, as shown in Fig. 3.

Referring in detail to the drawing, 1 indicates a tube support or so-called tube sheet which may comprise, if desired, a metallic plate 2 lined with a suitable high temperature refractory material 3. Plate 1 may usually be provided with a plurality of apertures 4 through which a corresponding plurality of tubes 5 may be inserted.

The tubes 5 may comprise a portion of the tube bank of a steam boiler, cracking still, or any such similar installation.

Considerable difliculty has heretofore been experienced in positioning tubes and removing same from the tube sheet because of the fact that the apertures 4 have been of a diameter which closely approximates the external diameter of the tube 5 positioned therein. The reason for this relatively tight fit of the tubes within the apertures 4 is to prevent leakage of the gases of combustion through the tube sheet around the tubes, and also to prevent the infiltration of cold air from without the tube sheet into the heating compartment of the furnace or boiler.

My invention has been particularly directed to the elimination of this disadvantageous feature present in the tube constructions heretofore uti-- lized and comprises a ferrule or bushing 6 which may be tubular in cross-section and be of substantially the same inner diameter as the outside diameter of the tubes used in the installation.

The outer diameter of the bushing 6 may be sub stantially that of. the aperture 4 so that when the bushing 6 is inserted in said aperture the same will be maintained therein by friction. The bushing 6 may be provided with an annular flange '7 which may prevent said bushing from slipping from its position within aperture 4. The bushing may be constructed of a metal having high heat withstanding characteristics, or 'may be constructed of a refractory material which may be cast and baked, or may be of any other suitable material which may be cast, moulded or otherwise formed.

To insure the maintenance of the bushing 6 within aperture 4 a clamp 8 may be suitably mounted at one end upon the outer wall of the tube sheet 1. One portion of the member 8 may be bent at right-angles to itself, as shown best at 9 in Fig. 1, the outer end of which may be adapted to contact flange '7 upon the bushing 6 and maintain said bushing in operative position within the aperture 4. A screw 10 may pass through the leg 9 of the clamp 8 and the end of said screw may be threaded into the wall of the tube sheet 1. In this manner by rotating screw 10 by means of a wing nut 11 or the like the member 9 can be made to firmly contact the flange '7 of the bushing 6.

Referring particularly to Fig. 3, a slight modification of my invention is shown wherein the numeral 12 may indicate a tube sheet, which in this instance is shown as a single metallic plate. It is to be understood, of course, that any type of tube sheet is contemplated by my invention. The sheet 12 may be provided with apertures 13 having diametrically opposite slots 14. A bushing 15 may be provided with a cylindrical portion 16 adapted to be inserted in the aperture 13 in the tube sheet, each end of the cylinder 16 terminating in flanged portions 17 and 18, being the inner and outer flanges, respectively. Diametrically opposite lugs 19 may be formed upon flangel'l, and similar lugs 20 may be formed upon the outer flange 18. If desired, the bushing may be so constructed that the lugs 19 and 20 will be removed from each other, as shown best in Fig. 4. The inner portion of the bushing 13 may be apertured as at 21 to receive a tube 22.

To mount this type of bushing the tube 22 may be inserted through aperture 13 in the tube sheet; Bushing 15 may be positioned upon the tube and the lugs 19 of the inner flange 1'7 may be brought into registration with the slots 14. The bushing may then be inserted through aperture 13 until the outer flange 18 contacts the outer face of the tube sheet 12. The bushing may then be rotated until both the inner lugs 19 and the outer lugs 20 are positioned adjacent solid portions of the tube sheet, this latter position being shown best in Fig. 4. The bushing 15 may be constructed of a material or materials similar to those enumerated in the construction of the bushing 6.

The material used in the construction of the bushing should preferably have about the same or a little greater co-efficient of expansion than the metal from which the tube or tube sheet is constructed. If a refractory material is used in the construction of the bushings the same may be constructed relatively inexpensively, and upon removing the tubes from the tube sheets the bushings may be broken to facilitate removal of said tubes.

I am aware that many modifications of the present device may be made without departing from the spirit of my invention and hence I do not wish to be limited except as necessitated by the prior art. a

I claim as my invention:

1. In combination, a destructible, non-metallic, non-corrosive bushing for use in a heating furnace and insertable between a heating tube and a tube sheet in a tube bank in said furnace, comprising a tubular member encircling said tube in non-leaking relationship at its point of passage through said tube sheet, and a flange integrally formed on said tubular member adapted to contact the face of said tube sheet.

2. In combination, a destructible, non-metallic, non-corrosive unitary bushing for use in a high temperature furnace and insertable between a heating tube and a tube sheet in a tube bank in said furnace, comprising a tubular member encircling and engaging said tube in gas-tight relationship at its point of passage through said tube sheet, and a flange integrally formed on said tubular member adapted to contact the face of said tube sheet.

3. In combination, a non-metallic, destructible, fireproof bushing insertable between a tube and a tube sheet in a tube bank employed in a hydrocarbon oil cracking furnace, comprising a tubular unit frictionally engaging and encircling said tube at substantially its point of passage through the tube sheet, and an integral flange formed on said tubular unit adapted to contact and abut the face of said tube sheet.

4. In combination, a non-metallic, non-corrosive, destructible bushing insertable between a tube and a tube sheet in a tube bank within an oil cracking furnace, comprising a tubular unit surrounding and frictionally engaging said tube in non-leaking relationship at substantially the point of passage of said tube through an aper ture in said tube sheet, flanges integrally formed on each end of said unit, lugs formed on each of said flanges, and slots adjacent said aperture in said tube sheet adapted to receive the lugs on said flanges.

5. In combination, a destructible bushing constructed of a refractory material and insertable between a tube and a tube support within a bank of tubes employed in a cracking furnace, comprising a unitary tubular member encircling and frictionally engaging said tube in non-leaking union at its point of passage through an aperture in said tube support, a plurality of integrally formed flanges on the opposite ends of said tubular member, adapted to contact with the opposite surfaces of said tube support, lugs formed on each of said flanges and slots formed in said tube support adjacent said aperture adapted to receive and retain the lugs on said flanges.

TEDDY B. FISHER. 

